Field of the Invention
This invention relates to sanitary drain fittings for connection to a water well head and is for automatically stopping flow from a water well pipe up stream from a down well water pump that feeds, for example, a stock tank, and allows water above the frost line to drain out of the water well pipe in a sanitary manner, avoiding damage to the down well water pump as will occur should the pump be operated to pump against a head of water frozen in a pipe above the frost line.
Prior Art
For down well water pumps that pump water to above the frost line, as into a stock tank, there exists a present need for an automatic, frost free, sanitary drain fitting for installation below at a water well head. When using a well for above ground applications, where the outlet pipe is exposed to freezing temperatures, the outlet pipe needs to drain below the frost line to avoid freezing in winter conditions, so as to avoid pumping against an ice plug that could damage the pump.
Heretofore, water wells have often been removed from service to avoid pump damage in freezing conditions, or the well exposed piping has been arranged to let water therein drain directly back into the well, potentially creating water well contamination. An example of such back flow arrangement for above-ground piping is outlined in instructions from Lorentz, the manufacturer of a pitless adaptor, that is shown as Prior Art in the Drawing Section of the present application, and which pitless adaptor is shown fitted with the sanitary drain valve of the invention. Where the Lorentz instructions call for forming a “weep hole” in a “drop pipe” that the pitless adaptor connects to, such that, when pumping is discontinued, water above the drop pipe will flow down the “drop pipe” and back to and through the “weep hole” and into the well casing. Which arrangement of forming such a “weep hole” and its draining back into the well casing may cause contamination of the well water, and is illegal.
The invention provides embodiments of a water well check valve that meets the requirements for being a legal sanitary valve in that it will not pass water back into the well when the pump is turned off. The check valve embodiments are each arranged is to be contained in a fitting body of an adapter arranged in the a well piping, and below the frost line. Which adapter is preferably a pitless adapter. Each check valve embodiment of the invention, with the pump operating, keeps a column of water flowing through a well outlet pipe for surface use, and closes when the pump is stopped to direct a water back flow from the outlet pipe and check valve through a drain pipe that passes through the adapter mount that dumps outside of the well casing, prohibiting a back flow into the well.